The present invention relates to an improved fluorescent lamp, and more particularly to a fluorescent lamp having a structure of two unitary conductive poles formed at two ends of the lamp tube respectively.
The well-known fluorescent lamp has various electrical power types of 10W, 20W, 40W and so on. In general, the conventional fluorescent lamp is designed to have shape of tube type, U-shaped type, or circular type. Typically, the fluorescent lamp has a pair of bi-pin filaments contained at each of the two ends of the lamp tube of the fluorescent lamp. Each of the filaments is led to the outer end point of the lamp, serving as a contact pin for connecting outer electrical power leads. That is, there are four contact pins in total and symmetrically formed at the two ends of the lamp tube. In order to start the lamp, it is necessary to first preheat the filament of the lamp by means of a starter, and then it is possible to ionize the inner gas in the lamp tube. Such a theory and the start operation of the fluorescent lamp has never changed since the fluorescent lamp was invented.
It is found that the conventional fluorescent lamp has disadvantages as follows:
1. During the pre-heating time of the lamp, the pre-heating current flowing through the filament is rather high and therefore the lamp consumes a large amount of electrical power. Further, the conventional fluorescent lamp needs a rather long pre-heating time to accomplish the start operation.
2. Because the initial current of the filament is relatively high during the start operation, the filament of the lamp is easy burned out or broken. Once the filament is broken, the fluorescent lamp will be useless.
3. The conventional fluorescent lamp must be provided with a starter to start the lamp by means of the starter. However, the starter often does not work normally due to faulty conditions. In such case, the starter must be replaced for maintaining the normal function of the start operation.
4. The lamp has in total four contact pins at two ends of the lamp. The possibility of faulty condition such as improper contact is relatively high because of more contact pins.
5. The fluorescent material in the lamp tube will be exhausted quickly during pre-heating period of the filament of the lamp.
6. The instant starting current of the lamp is rather large.
7. The starting time of the lamp is typically about 5 seconds. Obviously, in order to accomplish the start operation of the lamp, it will take much time.